During evaluation of a patient's foot, a physical therapy practitioner requires a means for dynamic measurement with respect to a subtalor neutral position, or optimal position, for foot function. The subtalor neutral position is characterized by the congruency of the head of the talus. During pronation, the talus will adduct and plantarflex; therefore the talar head can be palpated medially. Conversely, during supination the talus will abduct and dorsiflex, thus becoming more prominent laterally. To determine the subtalor neutral position of a patient's foot, the thumb and finger of the therapist is placed on the foot and the joint is alternately supinated and pronated until a position is found where the medial and lateral sides of the talus are neither protruding nor depressed between the finger/thumb placement. It is at this point that the congruency of the subtalor joint (with resulting neutrality) has been achieved.
Once a precise evaluation of the foot is obtained, the physical therapist can then recommend treatment to correct the flaws in the foot and restore ideal static and dynamic function to the foot. One such treatment is the use of an orthotic device, a custom made shoe insert designed specifically for the individual foot of the patient. Using the evaluation of the foot, the orthotic is constructed to mechanically force the foot into the subtalor neutral position for optimal foot performance. Of course, an accurate evaluation of the patient's foot is critical to the success of any orthotic.
Numerous devices have been developed over the years that examine the force distribution of the foot in both the static and dynamic environments. Although these evaluation tools have the ability to show forced production of a pathological foot, they do not provide specific objective measures of the foot that would provide the evaluator strategy for immediately restoring the ideal mechanics of the foot and to observe the immediate effects of the corrected posture.
The forgoing discussion suggests not only the desirability of a device and method for measuring the posture of a patient's foot, but also suggests the various applications for which such a device and method may be used. Accordingly, the present invention provides a solution to the problems mentioned above.